Statistical Research on Pulsars with the Gigahertz-Peaked Spectra

Abstract

The pulsar’s radio spectra in the high frequency shows the power law form in general, but people has also found 23 pulsars with the turn-over spectra peaking near GHz, i.e., the Gigahertz-peaked spectrum (GPS) pulsars. We launch the statistical research on these GPS pulsars, and find the peak frequency of 73.9% GPS pulsars in the sample is between 0.5 GHz and 1.0 GHz. The magnetic star has the higher peak frequency relative to other GPS pulsars, whose average peak frequency is 3.35GHz. The average spectral index of GPS pulsars is -1.33 which is higher than ones of ordinary pulsars. This phenomenon may be caused by the interstellar medium absorption for the pulsar’s radiation in the low frequency band. The statistical average of the dispersion measure of GPS pulsars is 348 pc cm-3, which is higher than the ones of ordinary pulsars. We also find the strong positive correlation between the period and dispersion measure of GPS pulsars, which imply that the interstellar medium may cause the pulsar’s rotation slow down.